CI_Encrypt::mcrypt_decode PHP Method

    public function mcrypt_decode($data, $key)
    {
        $data = $this->_remove_cipher_noise($data, $key);
        $init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
        if ($init_size > strlen($data)) {
            return FALSE;
        }
        $init_vect = substr($data, 0, $init_size);
        $data = substr($data, $init_size);
        return rtrim(mcrypt_decrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), "");
    }

$encryption = new CI_Encrypt();
$encryption->set_key(KEY);
// WRITE YOUR OWN COOKIE HERE!
$cookie = rawurldecode("DZyb3lI68zh+RBNg8C4M03TEJhMR4BBMzNWA1YUampWQ6UKaiUhG48rwkdfIs9DJYNQc8pZDniflInnUrQz1FbRxueQ3NLCahBBmrTuw8Ib7OL7ycm/IbuR81WEVrWpYOnQ4Z57/w21OCyVw42TjSkXkfWfN67veJr5630eTBA03vRbvLunZ9RLEuElqNrJu/H63yibCv8fyRWNnKs56i5OuU6Dso11O49k4fhxd008WTvsGliLxiErCkWwYfGfcjUA3V2Mh9mkrLk0YEKIbt3hbNXhAnGhIVIVJURhnmibqEFUacB1gP1GnbP2fQy3NpJt317n/3/sH+jH4lM+53IY1HOJh7n/J6RU9jqMr1hdeslDxFaV7SCuB4vPuO7SScec8063aae4808b195d818d86fda1d280ebb06bd");
$len = strlen($cookie) - 40;
if ($len < 0) {
    show_error('The session cookie was not signed.');
}
// Check cookie authentication
$hmac = substr($cookie, $len);
$session = substr($cookie, 0, $len);
if ($hmac !== hash_hmac('sha1', $session, KEY)) {
    show_error('The session cookie data did not match what was expected.');
}
// Detect target encryption method and Decrypt session
$_mcrypt = $encryption->mcrypt_decode(base64_decode($session));
$_xor = $encryption->_xor_decode(base64_decode($session));
$method = '';
$plain = '';
if (strpos($_mcrypt, KEYWORD) !== false) {
    _print("Encryption method is mcrypt!");
    $method = 'm';
    $plain = $_mcrypt;
} else {
    if (strpos($_xor, KEYWORD) !== false) {
        _print("Encryption method is xor!");
        $method = 'x';
        $plain = $_xor;
    } else {
        show_error("something went wrong.");
    }